But... (SPOILER ALERT)
To nitpick this movie isn't difficult.
1. The monsters are vulnerable to damage from conventional weapons, even as they inflict horrific damage to the robots. So why build robots that get up close and personal when the monsters have no discernible long range attacks? We currently have all sorts of super accurate guided missiles. Why not equip these robots with such weapons and blast the beasts from out of harm's way? Not very cinematic, I guess.
2. Why do they let the monsters reach major cities before engaging them? They know where the monsters come from. Why not build a base and blast them out in the middle of the Pacific?
3. Why exactly does it take two to tango or operate a giant robot? Some nonsense about "neural load" but really just to create an obstacle in the plot.
4. If the pilots are mentally linked why do they keep asking each other "Are you okay?" Why do they talk to each other at all? Wouldn't they already know?
5. Why are the pilots actually inside the robots where they can be killed during the fight? Why not operate them remotely? Much safer. And we already do this sort of thing with TODAY'S technology.
The answer to all these question is that the writers thought these things would make the movie more exciting. Who wants to watch a desk jockey push a button and beat a monster by remote control? But still, I can imagine a giant robot movie where you pay attention to things like logic and common sense that still conveys the horror of these creatures.
Don't get me wrong, I loved watching a robot drag a huge tanker ship through Hong Kong and use it to batter a monster. But, really, why??? Doesn't the robot have a whole bunch of weapons? Were there any people on that ship? How do they know?